NATURAL AND ARTIFICIAL RADIOACTIVITY IN BULGARIAN SOILS ALONG THE DANUBE RIVER

Data from gamma-spectrometry analyses of soils and sediments samples taken along the Danube river is presented in the paper. Results about the content of natural and artifi cial radionuclides like Sr-90 and Cs-137 are discussed. The region around the Kozloduj NPP including its exclusion zone is investigated in more details. Data from the last years is compared with such from former investigations of similar samples from the region. The soil is a natural depot and initial reservoir for spreading of all man-made radionuclides and natural radioactivity. The man-made isotopes with the longest half-life time, like Sr-90 and Cs-137 are mainly investigated. Because of their feature to be bioelements, that is to include themselves in human’s metabolism, they are especially dangerous when their concentrations in the nutritious chain increase. That is why the investigation of these nuclides together with the natural once like uranium, thorium and radium started in 1978 with annual determination of their concentrations in soils collected from the region of “Kozloduj” NPP and some places along the Danube river potentially exposed to radioactive contamination. The aim was to make a picture of the radioecological status of the soils along the Danube river. The period after 1986 is concerned as the accident in Chernobyl’s NPP changed basically the radioactive situation in the country

УСВОЯВАНЕ НА CS-134 В ОВЕС В ЗАВИСИМОСТ ОТ ПОЧВЕНИТЕ ХАРАКТЕРИСТИКИ

Vegetation pot experiments with spring oats, cultivar Obrazcov Chifl ik – 4, were carried out. The plants were grown on four different soil types, typical for Bulgaria: Haplustoll, Udolls, Ustifl uvents, Albaqualf /USA. The soils were contaminated with the Cs-134. It was concluded that the radio-caesium accumulates unevenly in the different plant organs, as its highest concentration was found in the leaves and lowest in the grains of the researched culture. Substantial differences were discovered in the accumulation of caesium –134 in the plants, depending on the soil differences. According to the accumulation of the radio-caesium in the plants, the different soils can be arranged as follows: Albaqualf > Vdolls >Ustifl uvents > Haplustoll.Проведени бяха съдови опити с пролетен сорт овес Образцов Чифлик-4. Растенията бяха отгледани върху орницата на четири почвени различия, харакрерни за България и контаминирани с радионуклида цезий- 134. Експериментите бяха проведени върху почви, различаващи се по механичен и физикохимичен състав: Haplustoll, Udolls, Ustifl uvents, Albaqualf / USA. Констатирано бе, че радиоцезия се натрупва неравномерно в различните органи на растенията, като най-висока концентрация бе установена в листата, а най-ниска в зърната на изследваната култура. Установени бяха съществени различия в усвояването и натрупването на цезий-134 в растенията в зависимост от почвенoтo различиe. Според акумулацията на радиоцезия от растенията, изследваните почви могат да се подредят в следния ред : канелено подзолиста > сива горска почва > алувиално.ливадна > излужен чернозе

ЕСТЕСТВЕНА И ИЗКУСТВЕНА РАДИОАКТИВНОСТ В БЪЛГАРСКИ ПОЧВИ ПО ПОРЕЧИЕТО НА РЕКА ДУНАВ

Data from gamma-spectrometry analyses of soils and sediments samples taken along the Danube river is presented in the paper. Results about the content of natural and artifi cial radionuclides like Sr-90 and Cs-137 are discussed. The region around the Kozloduj NPP including its exclusion zone is investigated in more details. Data from the last years is compared with such from former investigations of similar samples from the region. The soil is a natural depot and initial reservoir for spreading of all man-made radionuclides and natural radioactivity. The man-made isotopes with the longest half-life time, like Sr-90 and Cs-137 are mainly investigated. Because of their feature to be bioelements, that is to include themselves in human’s metabolism, they are especially dangerous when their concentrations in the nutritious chain increase. That is why the investigation of these nuclides together with the natural once like uranium, thorium and radium started in 1978 with annual determination of their concentrations in soils collected from the region of “Kozloduj” NPP and some places along the Danube river potentially exposed to radioactive contamination. The aim was to make a picture of the radioecological status of the soils along the Danube river. The period after 1986 is concerned as the accident in Chernobyl’s NPP changed basically the radioactive situation in the country.В работата са представени резултати от гама-спектрометрични анализи на почви и седименти от поречието на р. Дунав. Обсъдени са данни за съдържанието на естествена радиоактивност и техногенни радионуклиди, като Sr-90 и Cs-137. По-детаилно е проучен района около АЕЦ “Козлодуй” заедно със санитарно защитената зона. Сравнени са данни от последната година с такива от изследвания на проби от този район извършени в предишни години. Почвата е естествено депо и първичен резервоар за разпространение на всички изкуствени радионуклиеди и естествена радиоактивност. Изслезвани са главно техногенните радиеонуклиди с най-дълъг период на полуразпад, като Sr-90 и Cs-137. Поради характеристиките им на биоелементи, т.е да се включват в метаболизма на човека, те са особено опасни при увеличаване на концентрацията им в хранителната верига. Поради това от 1978 започва изследването на тези радионуклиди едновременно с естествени, като уран, торий и радий, като се прави ежегодно определяне на концентрациите им в почви, събирани от района на АЕЦ “Козлодуй” и някои области по поречието на р. Дунав, потенциално изложени на радиоактивно замърсяване. Целта е да се изработи картина на радиоекологичния статус по поречието на р. Дунав. Разглеждан е периода след 1986 г., тъй като инцидента в Чернобилската АЕЦ, промени основно радационната обстановка в страната

ACCUMULATION OF 134CS IN THE PEPPER DEPENDING ON SOIL CHARACTERISTICS AND METHODS FOR REDUCTION OF THE TRANSFER OF RADIONUCLIDES FROM THE SOIL INTO THE VEGETATION PRODUCTION

The particularities of the soil as sorbent, its complex composition and the differences in its properties impose the research of the accumulation of the The development of methods for reduction of the transfer of radionuclides from the soil into the vegetation production being of particular signifi cance for the implementation agricultural activities in conditions of radioactive pollution of the soil, the impact of potassium, calcium and EDTA or ethylenediaminetetraac etic acid over the accumulation of radio-caesium from the soil into the plants. As it is seen from the results presented, the input of potassium, calcium and EDTA in the Orthic Luvisols signifi cantly decreased the input of Сs-134 into the pepper plants.Особеностите на почвата като сорбент, сложния и състав и различията в свойствата и налагат изследването на усвояването на радиоактивните елементи от растения, отглеждани на типични за България почви. От особена важност за провеждането на земеделска дейност в условия на радиактино замърсяване на почвата е разработването на методи за намаляване трансфера на радионуклидите от почвата в растителната продукция, беше изследвано влиянието на калий, калций и ЕДТА върху натрупването на радиоцезия от почвата в растенията. От получените резултати може да се каже, че с внасянето на калий, калций и ЕДТА в сивата горска почва, значително се намалява постъпването на Сs-134 в растенията

Optical measurements of electrophoretic suspension kinetics

Electrophoretic deposition (EPD) was originally used for formation of coatings, e. g. in the automotive industry. Recently EPD is successfully utili zed for thin film preparation with an app lication in the optics and electronics. This paper investigates the process of the suspension formation and aggregation by ultraviolet and visible spectroscopy (UV- VIS) spectroscopy and Dynamic Light Scattering (DLS) methods. The suspensions were formed by a precipitation of solution of poly[2-methoxy-5-(3 ′ ,7 ′ -dimethyloctyloxy)-1,4-phenylenevinylene] in toluene using acetonitrile as a precipitator. It could be concluded that the progressive suspension particle growth observed by DLS affects regularly the first derivative of the UV-VIS spectra. By a comparison of the results obtained by both methods it could be seen that UV-VIS spectroscopy combined with the spline method could be successfully used for an estimation of electrophoretic suspensions

Kinetic Generation of Whistler Waves in the Turbulent Magnetosheath

The Earth's magnetosheath (MSH) is governed by numerous physical processes which shape the particle velocity distributions and contribute to the heating of the plasma. Among them are whistler waves which can interact with electrons. We investigate whistler waves detected in the quasi-parallel MSH by NASA's Magnetospheric Multiscale mission. We find that the whistler waves occur even in regions that are predicted stable to wave growth by electron temperature anisotropy. Whistlers are observed in ion-scale magnetic minima and are associated with electrons having butterfly-shaped pitch-angle distributions. We investigate in detail one example and, with the support of modeling by the linear numerical dispersion solver Waves in Homogeneous, Anisotropic, Multicomponent Plasmas, we demonstrate that the butterfly distribution is unstable to the observed whistler waves. We conclude that the observed waves are generated locally. The result emphasizes the importance of considering complete 3D particle distribution functions, and not only the temperature anisotropy, when studying plasma wave instabilities.Peer reviewe

Effect of foliar products on the inflorescence yield of lavender and essential oil

Received: January 25th, 2022 ; Accepted: May 1st, 2022 ; Published: May 23rd, 2022 ; Correspondence: [email protected] topic of the effect of foliar fertilization on the productivity and oil content of lavender is relevant, but not sufficiently studied. The present study aims to establish the effect of foliar products on the growth, development and productivity of lavender. The field experiment was carried out at the Agricultural University - Plovdiv with lavender of ‘Jubileina’ variety during 2019–2020. The following variants were included in the study: 1. Untreated control; 2. Treatment with Fertileader Gold (FG) - 3 L ha-1; 3. Treatment with Fertiactyl Trium + Fertileader Vital (FT + FVital) - 1.5 + 1.5 L ha-1; 4. Treatment with Fertileader Viti (FViti) - 3 L ha-1; 5. Treatment with Fertileader Vital (FV) - 3 L ha-1; 6. Treatment with Fertileader Alpha (FA) - 3 L ha-1. Those preparations are bio stimulants for foliar application. The treatments were made in two consecutive lavender vegetation seasons. The first application was carried out in the second growing season (2019) and the second in the next, third growing season (2020). The foliar application of all tested products increased the photosynthetic activity, but it was better expressed when using the plant nutrition products FV, FViti and FT + FVital. A positive effect was also observed in the height and diameter of the bush, but during the third vegetation period. The number of flowering stems increased by 62.9%; 59.4%; 53.3% and 8.4%, respectively, when applying the fertilizers FG, FT + FVital, FViti and FV. The application of FG and FT + FVital increased the yield of fresh inflorescences by 6.1% and 3.7%. The application of the different products affected the oil yield in different ways; the application of FG, FT + FVital and FViti increased it, while FV and FA decreased it by 27 kg ha-1 and 16 kg ha-1, respectively, for the first vegetation and by 43.4 kg ha-1and 33.1 kg ha-1 for the second vegetation. The boron containing products FG, FT + FVital and FViti led to a significant increase in the essential oil yield, while the application of the foliar fertilizers FV and FA reduced it. Based on those results, the first three products are recommended

УСВОЯВАНЕ НА 134Cs ОТ КОНТАМИНИРАНИ ПОЧВИ В РАЗЛИЧНИ СОРТОВЕ ТРИТИКАЛЕ И ОВЕС

Pot experiments with different triticale and oats varieties spread in Bulgaria were carried out. Three varieties of triticale (Rakita, TC-210, AD-7291) and three varieties of oats (Obrazcov chifl ik, W-!6 and W-17) were analized. The plants were grown on soil type Dystric planosol /FAO. The soil was contaminated with radionuclide 134Cs. It was established that the radiocesium is unevenly accumulated in the different parts of the plants. The highest 134Cs concentration was found in the leaves and the lowest in the grains. Variety differences of uptake of 134Cs in investigated crops were established. The highest level of accumulation of the radiocesium has been detected in triticale variety Rakita, and in oats variety W-17. It has been determined that the uptake of the radionuclide by plants of the triticale is more intensive then that of by the oats plants.Проведени бяха съдови опити с различни сортове тритикале и овес, разпространени в България. Анализирани бяха 3 сорта тритикале: (Ракита, ТС-210, АД-7291) и 3 сорта овес: (Образцов чифлик 4, W-16 и W-17). Растенията бяха отгледани върху канелено подзолиста почва, контаминирана с радионуклида цезий-134. Констатирано бе, че радиоцезия се натрупва неравномерно в различните органи на растенията. Най-висока концентрация бе установена в листата, а най-ниска в зърното на изследваните култури. Установени бяха сортови различия в усвояването на 134Cs от изследваните култури. Най-висока степен на натрупване на радиоцезия бе отбелязано при тритикале сорт Ракита, а при овеса в сорт W-17. Наблюдавани са видови различия при натрупването на радионуклида в изследваните култури. Тритикалето има подчертана способност да извлича от почвата и акумулира радиоцезия в надземните органи по-силно от овеса

IN VITRO ASSESMENT OF 0.2 % ZINC-HYALURONATE ACTIVITY AGAINST MICROORGANISMS ISOLATED FROM PATIENTS WITH DIFFICULT HEALING LEG ULCERS

ABSTRACT The development of wound infection and selection of resistant microorganisms is a significant problem in the proces